{{short description|Division of the forebrain around the third ventricle}} {{Infobox Brain| Name = Diencephalon | Latin = diencephalon | Image = File:Illu diencephalon.jpg | Caption = The hypothalamus and the right and left halves of the thalamus are labeled. The cerebellum is not part of the diencephalon.| part_of = [[Human brain]] | Components = [[Thalamus]], the [[hypothalamus]], the [[epithalamus]] and the [[subthalamus]] | Artery = | Vein = | Precursor = [[Prosencephalon]], derived from the [[neural tube]] }}
In the [[human brain]], the '''diencephalon''' (or '''interbrain'''<ref>{{Cite web|title=Interbrain {{!}} anatomy|url=https://www.britannica.com/science/interbrain|access-date=2021-05-07|website=Encyclopedia Britannica|language=en}}</ref>) is a division of the [[forebrain]] (embryonic ''prosencephalon''). It is situated between the [[telencephalon]] and the [[midbrain]] (embryonic ''mesencephalon''). The diencephalon has also been known as the '''tweenbrain''' in older literature.<ref name="Cloake">{{cite journal |last1=Cloake |first1=P |title=The Influence of the Diencephalon ('Tween Brain) on Metabolism. |journal=Proceedings of the Royal Society of Medicine |date=August 1927 |volume=20 |issue=10 |pages=1643–56 |doi=10.1177/003591572702001036 |pmid=19986038|pmc=2100946 }}</ref> It consists of structures that are on either side of the [[third ventricle]], including the [[thalamus]], the [[hypothalamus]], the [[epithalamus]] and the [[subthalamus]].
The diencephalon is one of the main [[brain vesicle|vesicles of the brain]] formed during [[human embryonic development|embryonic development]]. During the third week of development a [[neural tube]] is created from the [[ectoderm]], one of the three primary [[germ layer]]s, and forms three main vesicles: the [[prosencephalon]], the [[Midbrain|mesencephalon]] and the [[Hindbrain|rhombencephalon]]. The prosencephalon gradually divides into the telencephalon (the [[cerebrum]]) and the diencephalon.
==Structure== The diencephalon consists of the following structures:{{cn|date=June 2024}} * [[Thalamus]] * [[Hypothalamus]] including the [[posterior pituitary]] * [[Epithalamus]] which consists of: ** Anterior and posterior [[paraventricular nuclei]] ** Medial and lateral [[habenular nuclei]] ** [[Stria medullaris thalami]] ** [[Posterior commissure]] ** [[Pineal body]] * [[Subthalamus]]
===Attachments=== The [[optic nerve]] (CNII) attaches to the diencephalon. The optic nerve is a sensory (afferent) nerve responsible for [[Visual perception|vision]] and [[sight]]; it runs from the eye through the [[optic canal]] in the [[human skull|skull]] and attaches to the diencephalon. The [[retina]] itself is derived from the [[optic cup (embryology)|optic cup]], a part of the embryonic diencephalon.{{cn|date=June 2024}}
==Function== {{Cleanup rewrite|date=November 2023|it uses non-scientific language and lacks citations|section=yes}} The diencephalon is the region of the embryonic vertebrate [[neural tube]] that gives rise to anterior [[forebrain]] structures including the [[thalamus]], [[hypothalamus]], [[Posterior (anatomy)|posterior]] portion of the [[pituitary gland]], and the [[pineal gland]]. The diencephalon encloses a cavity called the third ventricle. The thalamus serves as a relay centre for sensory and motor impulses between the spinal cord and medulla oblongata, and the cerebrum. It recognizes sensory impulses of heat, cold, pain, pressure etc. The floor of the third ventricle is called the hypothalamus. It has control centres for control of eye movement and hearing responses.
==Additional images== <gallery> Image:EmbryonicBrain.svg |Diagram depicting the main subdivisions of the embryonic vertebrate brain. These regions will later differentiate into forebrain, midbrain and hindbrain structures. Image:Gray645.png |Reconstruction of peripheral nerves of a human embryo of 10.2 mm. (Label for Diencephalon is at left.) </gallery>
==See also== * [[Diencephalic syndrome]] * [[List of regions in the human brain]]
== References == {{Gray's}} {{Reflist}}
==External links== * {{BrainMaps|diencephalon}} * [https://www.neuinfo.org/mynif/search.php?q=Diencephalon&t=data&s=cover&b=0&r=20 NIF Search – Diencephalon] {{Webarchive|url=https://web.archive.org/web/20200413073731/https://neuinfo.org/data/search?q=Diencephalon&t=data&s=cover&b=0&r=20 |date=2020-04-13 }} via the [[Neuroscience Information Framework]] {{Medical resources}} {{Nervous system}} {{Diencephalon}} {{Portal bar|Anatomy}} {{Authority control}}
[[Category:Diencephalon| ]] [[Category:Animal developmental biology]]